Shanster,
I own a 26" WJ Jefferey 450/400 in 3" cordite, hammerless.Am in the process of restoring it-reblue, do up the stock a bit and most imp, the folding leaf sights-I have put away perhaps 30 rounds thru it and can endorse the feelings of the forum-this is one sweetheart to shoot.
I've only used Eley kynoch 450/400J ammo and have no experience in hand loading.Am sourcing more and hope to have a loud christmas!
best
Axx